Rock bit



l Oct. 8, 191110. T. H. sTANcLlFF ROCK BIT Filed Oct. l2. 1939 2 Sheets-Sheet 1 @Ufo/meg Od 8f1940.- T. H. STANCLIFF. 2,216,894

` ROCK BIT 2 Sheets-Sheet 2 Filed Oct; l2. 1939 Vui lao

Patented oct. s, 1940r BQCK BIT Thomas H. Stanclil', I-Iouston, Tex., assignor to Reed Roller Bit Company, Houston, Tex., a

corporation of Texas Application October 12, 1939, Serial No. 299,069

f This invention relates to rock bits, and more particularly to those in which the cutter assembly is attached to the bit head by depending legs, and has for its general object the provision of a means for mounting a cutter assembly of this type on a bit head.

In order to provide the necessary rigidity and durability, cutters are usually mounted on shafts which are welded or otherwise permanently sec ured to the bit head. It is desirable, however, that the cutters be detachable so that they may bereadily removed and replaced when worn. Itis an object of this invention therefore to provide a meansfor securing a cutter assembly to a bit `head rigidly yet in a'manner which will render it readily detachable.

It is a further object to provide a structure in which the cutters may be first assembled and then detachably secured to the bit head as a unit.

Further objects and features will becomev evident from the following disclosure, taken in connection with the accompanying drawings, in

Figure 1 is a longitudinal cross section of a bit embodying my invention;

.'Figure 2 is a lfragmentary side elevation of the bit shown in Fig. 1, showing'the manner of se.-

curing the legs supporting the side cutter to the bit head. f

Figure 3 is a cross section taken along. line 3--3 of Fig. 2;

Figure 4 is a cross-section taken along liner,

4 4 of Fig. 2,;

Figure 5 is a longitudinal cross vsection of the same bit taken at right angles to Fig. 1..

Figure 6 is a view similar lto Fig. 2 showingthe manner of securing the legs supporting the cross cutters to the bit head.

Figure I is across section taken along line 1-1 of Fig.6; and v v Figure 8 is a cross section taken along line 8--8 of Fig. 6.

. Referring to the drawings in detail, a bit body III has, made integral therewith, the depending tongues II. These tongues are beveled inwardly on their sides as shown at l2 to provide a dove tail cross section and inwardly and upwardly on after explained.

theirbottom ends as at I3. Above the tongue'.

portions Il there are formed in the side of the bit body. recesses I4,

Detachable legs I5 and I5"are formed with bil furcated upper portions forming extensions I6 which form between them dovetail openings or slotsnarrower at their limer portionsthanat their outer v.to receive and conform to the tongues II, with the beveled portions I2. Likewise, the

bottom of each groove is slanted upwardly and inwardly to conform to the bevel portion I3. By

these means the legs, when iitted onto the bit,

for a purpose to be herein- 'z claims. (ci. c55- 71) are securely held against lateral displacement.

Also formed in the .sides of the bit body I0 are slots I1,A extendingbelow the recesses I4 and traversely of and above the tongues II. Carried in these slots are bars I8, Whose purpose is to assist in holding the legs I5 and I5 in place. This is done by means of bolts or studs I9 in the upper ends of the leg extensions I6, these bolts or studs extending vthrough holes in the bar I8 into bit is illustrated. In these 4ilgures the legs I5 are provided adjacent their lower ends with open.

ings 22 .which receive the outer ends of a bridge 23 and are welded in place thereon as illustrated inFig. l; The bridge 23 is formed just inwardly of its outer ends with suitable bearing recesses for receiving anti-friction bearings 2,4 and 25 upon which the side cutters 26 are rotatably mounted.

` These cutters are first mounted on the bridge and the legs I5 are then placed'over the ends of the bridge and welded in place thus servingA to confine' the cutters to their proper position on the bearing portion of the bridge. y I

The central portion of the bridge is provided with an opening 21 in which is received the inner ends of the cross cutter bearing shafts 28 and 29. These shafts are integral with the legs I5 illustrated in Figs; 5 to 8, inclusive, and their inner ends'are secured in position within the opening in the bridge -by any suitable means such as by the welding arrangement 30 illustrated in Fig. 5.

The shafts 28 and 29 arewprovided with recesses 'adapted to receivesuitable 'radial bearings 3| and 32 arid-suitable bali mwst-bearings '.which provide forthe rotatableV support'of the cross roller cutters 2 I.

In assemblying `the device just deseribecl';y thev Iside cutters 26 laremounted upon the ends of the bridge vin the position illustrated and after theL proper anti-friction bearings 24 and 25 have been put in place, the legs I5 are placed over the ends of the bearing portions of the bridge and welded in place are placed over their respective stud shafts on the arms I5' with the anti-friction bearings illustrated in their proper position therein. The

inner ends of these stud shafts are then inserted.`

as shown.' The cross roller cutters 2| into the bridge and weldedin position, as shown -.tt-BIL The unit as a whole may then be moved on to the shank or head portion of the bit I0 and the extensions of the respective arms I5 and I5' are engaged with the dovetail tongues I I on the body. l

The studs and bolts I9 are then put into position and tightened so as to draw the entire unit posed within therecesses I4 and are available for tightening for this purpose.

By the structure set out above. I have produced a rock bit with a cutter assembly which is detachable and replaceable in a highly efficient manner, so that, when a cutter or cutters become worn out or damaged, this cutter or the entire cutter assembly may be changed and the entire bit need not be replaced. I do ot wish to be limited to the specific embodi 'ents disclosed herein, but only by the scope of the appended claims.

I claim:

1. In a rock bit, a/bit head having a plurality of integral tongue members extending outwardly 'from vertical side faces on said bit head, said cure said detachable legs on the bit head against lateral displacement, and means for holding said legs against longitudinal displacement.

2. In a rock bit, a bit head having a plurality of integral tongue members extending outwardly from vertical side faces on-said bit head, said tongue members having wedge-shaped outer portions whichl 'taper inwardly relative to the bit head axis, detachable legs having slots therein fitted on said tongue members, said side faces cooperating with said tongue members to rigidly secure said detachable legs on the bit head against lateral displace each of said tong e members being inclined downwardly and outwardly relative to said bit head axis and their inner ends stopping abruptly at a vertical shoulder on each of said tongue members to assist in preventing lateral displacement, and means for holding said legs against longitudinal displacement.

3. In a rock bit, a bit head havingV a plurality of integral tongue members extending outwardly from vertical side faces on said bit head, said tongue members having wedge-shaped outer portions which taper inwardly relative to the .bit head axis, detachable legs having slots therein fitted on said tongue members, cutter means held between the legs, said side faces cooperating with said tongue members to rigidly secure said detachable legs on the bit head against lateral displacement, and means for holding said legs against longitudinal displacement.

4.- In a rock bit, a bit head having a plurality of integral tongue members extending outwardly from vertical side faces onsaid bit head, said tongue members having wedge-shaped outer portions which taper inwardly relative to the bit head ent, the bottom end surfaces of on each of said tongue members to assist in preventing lateral displacement, and means for holding said legs against longitudinal displacement.

5. In a rock bit, a bit head having a plurality of integral tongue members extending outwardly from vertical side faces on said bit head, said tongue members having wedge-shaped outer portions which taper inwardly relative to the bit head axis, detachable legs having slots therein tted on said tongue members, cutter means journaled between the legs, said side faces cooperating with said tongue members to rigidly secure said detachable legs on the bit head against lateral displacement, the bottom end surfaces of each of said tongue members being inclined downwardly and outwardly relative to. said bit head axis and their inner ends stopping abruptlyataverticalshoulder on each of said tongue members to assist in preventing lateral displacement, transverse slots and recessesinsaidbithead above said tongues, bars in the slots, bolt means for holding the legs on said bit head, said bolt means extending through said bars and having parts in said recesses whereby they may be tightened.

6. In a rock bit, a bit head having a plurality of integral tongue members extending outwardly from,y vertical side yfaces onl said bit head, said tongue members having wedge-shaped outer por-` tions which taper inwardly relative to the bit head axis, detachable legs having slots therein fitted on said tongue members, apertures in the bottom ends of said legs, a cutter shaft mounted. in each of said apertures, said side faces cooperating with said tongue members to rigidly secure said detachable legs on the bit head against lateral displacement, the bottom end surfaces of each of said tongue members being inclined downwardly and outwardly relative to said bit head axis and their inner ends stopping abruptly at a vertical shoulder on each of said tongue members to assist in preventing lateral displacement, transverse slots and recesses in said bit head above said tongues, bars .1in the slots, and means for l holding said legs on said bit head, said means comprising bolts extending from the -upper ends of the legs through the bars into the recesses, and lock nuts on the bolts in the recesses.

'1. in a. rock bit, a bit head having a. plurality of integral tongue members extending outwardly from vertical side faces on said bit head, said tongue members having wedge-shaped outer portions which taper inwardly relative to the bit head axis, detachable legs having slots therein fitted on said tongue members, stubl shafts on the bottom ends of said legs, a cutter assembly journaled on said tub shafts, said 'side faces cooperating with said tongue members to rigidly secure said detachable le`gs on the bit head against lateral displacement, the bottom end surfaces of each of said l tongue members being inclined downwardly and outwardly relative to said bit head axis and their inner ends stopping abruptly at a vertical shoulder on each of said tongue members to assist in preventing lateral displacement, transverse slots and recesses in said bit head above said tongues. bars in the slots and means for holding said legs on said bit head, said means consisting of threaded holes in the'upper ends of the legs and bolts, with their heads in said recesses, extending through the bars and into the threaded holes.

THOMAS H. STANCLIFF. 

